pub fn new_birthday_probability(number_of_people: u32) -> f64 {
    const DAYS_IN_YEAR: u32 = 365;

    if number_of_people > DAYS_IN_YEAR {
        return 1.0;
    }

    let mut probability_all_unique = 1.0;

    for person_index in 1..number_of_people {
        probability_all_unique *= (DAYS_IN_YEAR - person_index) as f64 / DAYS_IN_YEAR as f64;
    }

    1.0 - probability_all_unique
}
